Most likely it’s spurious error to be safely ignored. Do you see an option to say OK to the message? Generally, doing that makes it go away and not come back. You won’t see any additional charges for international roaming or otherwise. As a prepaid service, there are never additional charges with Republic beyond monthly plan fees.

Most Republic plans don’t offer roaming data. Since you happen to be on a grandfathered Republic Refund plan with your Moto G3, you do have the option of accessing roaming data. There isn’t any surprise fee for doing that per se, however, roaming data is used 18.3x faster than native data making the effective cost $274.50 per GB. Therefore, I’d suggest using it only in an emergency. Again, to be clear for others who may be reading, no surprise fee but any cell data purchased would be used much faster when roaming.

Looks like I’m at least the 3rd person to have this issue since 7/30…there is this post and one other in the forum & it just started last night for me. (Of course, it happened during the middle of an emergency while I was trying to call my boss!) It’s even happening when I try to call out on wi-fi if my cell service isn’t turned off.